args=(commandArgs(TRUE))
for(i in 1:length(args)){
    eval(parse(text=args[i]))
}
model = as.formula(paste("Surv(",time,",",status,") ~ ", predictors))
library(paf)
library(foreign)
test = read.dta(datafile)
cov = strsplit(cov, split=",")[[1]]
result=paf(model, data=test, cov=cov)
print(result$fit.cox)
result1 = data.frame(time=result$time, est=result$est, se=result$se, low=result$low, upp=result$upp)
write.dta(result1, file=resultfile)